In vitro quantitative measurements and analyses of various intracellular parameters is becoming an important aspect in cell research. Comprehensive understanding of a single cell in response to its biological environment and stimuli is becoming the foundation of many biomedical research fields, including drug development, nanotoxicity study, biomarker discovery, cancer diagnosis and treatment, and many other areas. However, there is no such instrument currently available to perform comprehensive, quantitative measurement of various key parameters inside a cell simultaneously. This project aims to develop a novel multi-functional single-cell analyzer that integrates the capability of in vitro measurements of a number of important intracellular parameters. The new cell analyzer will address a number of critical issues in biomedical research such as cell necrosis and apoptosis, stem cell differentiation, and cancer cell biology. Three specific aims are designed in this project, including: 1) Development of tapered-fiber microprobes and associated instrumentation for in situ measurement of intracellular pH, temperature, and Raman spectroscopy; 2) Integration of tapered-fiber microsensors with morphology and structure monitoring capabilities to construct the single-cell analyzer; and 3) Evaluation and demonstration of the multi-functional single-cell analyzer using cytotoxicity of nanomaterials as an application model. The proposed novel single-cell analyzer is uniquely enabled by a number of key innovations embedded in this project. Assembly-free micro- and nano-size sensor probes will be designed and fabricated on the distal end of optical fiber tapers that can be directly inserted into a livin cell for in situ, quantitative measurement of various important parameters with high resolution. The innovative integration of these microsensors with microscopic imaging tools will allow comprehensive, systematic studies of the cell responses to the bio-environment and stimuli. The use of cytotoxicity of nanoparticles as an example to evaluate and demonstrate the basic functions of the single-cell analyzer will also provide valuable information for further performance enhancement, system optimization, and expansion of applications. The proposed research will be conducted by a multidisciplinary team consisting of three professors at Missouri University of Science and Technology (Missouri S&T). All major equipment required for this project is available on Missouri S&T campus. The team members have complementing skills in biochemistry/bioanalysis, cytotoxicity of nanomaterials, optical micro/nano sensors and instrumentation, and analytical instrument design and implementation. The interdisciplinary project of life science, electrical engineering, and chemistry will foster strong collaborations among faculty and students in different fields, and strengthen the biomedical- related research and infrastructure at Missouri S&T.